Biological Extraction Methods Research Articles

Comparison of Morphological and Chemical Properties of Musa Velutina Fiber Extracted through Different Extraction Method

ABSTRACT Natural fibers are being used for the last few decades as an alternative to synthetic fibers for their eco-friendly nature. But still, there is a scientific gap to address cost-effective and environmentally sustainable fiber extraction method with minimum waste production. Therefore, a study was carried out on the extraction of fiber from naturally occurring Musa velutina (wild banana plant) adopting different extraction methods. Wild banana plant fiber was extracted by chemical and biological process. Chemical extraction was carried out using Sodium hydroxide at two different concentrations (3% and 5%). The temperature was maintained at 100 ± 50°C and the bath ratio maintained at 1:7 for 2 h. Fiber yield was obtained from 20.32% to 22.56% for both concentrations. Similarly, the biological retting process was also executed using potential lignolytic bacterial (e.g. Bacillusacidicola) and fungal (e.g. Chaetomium sp.) strains. Fiber yield in the biological process was obtained at the range 21.32–31.02%. Proximate chemical analysis and SEM of extracted fiber were determined. Among the methods, the biological extraction method is found suitable in comparison to the chemical process.

Kinetic Study of Subcritical Water Extraction of Carbohydrate from Microalgae Nannochloropsis sp.

Microalgae contain a significant amount of carbohydrates that can be converted further to produce valuable compounds. To extract carbohydrates from microalgae, sub-critical water extraction (SWE) is a viable and novel method. Compared to other existing chemical and biological extraction methods, SWE is more economical, effective, and efficient in terms of process conditions. This process uses high temperature and pressure of water at just below supercritical conditions to keep water at a liquid state. This study aims to investigate the factors that affect the extraction yield of carbohydrates from microalgae Nannochloropsis sp. using the SWE process. The extraction was carried out at a temperature of 160 – 320 oC, a duration of 5 – 25 min, and microalgal biomass loading of 5 - 25% w/v. The kinetics study was conducted in an extraction time of 5 – 25 min at 200 oC and 5% (w/v) biomass loading. A simplified kinetic model based on a consecutive reaction was used to describe carbohydrate production and decomposition via SWE. It was found that the maximum yield of total carbohydrate was 18.04 g/100 g which was obtained at 200 oC, 10 min, and 5% (w/v) microalgal biomass loading. The carbohydrate concentration was decreased as the temperature, extraction time and microalgal biomass loading increased. This result indicated that the SWE is a promising extraction method for carbohydrate recovery from microalgae, and the factors investigated here had a significant effect on the extraction process. The proposed kinetic model was also able to capture the experimental data well within the range of operating conditions studied in this work.

The bioextraction of bioplastics with focus on polyhydroxybutyrate: a review

Use of bioplastics such as polyhydroxybutyrate (PHB) is increasing steadily. PHB extraction methods including solvent extraction and chemical digestion surfactant require the harmful reagents and result in severe quantitative and qualitative environmental and economic losses. Due to the friendly properties, biological extraction methods (called bioextraction methods) are gaining more attention to PHB extraction. Bioextraction methods can reduce the serious concerns in environmental pollution and cost by green tools such as genetic and metabolic engineering of PHB-accumulating cells in order to self-disrupt, induce, and modify predatory bacteria, and the utilization of mealworm digestive system. Through biotechnology mechanisms, a purified PHB biopolymer can be extracted by manufacturers in a eco-friendly system, while water and acetic acid can then be used for pre-treatment other than SDS and chloroform. As in many aspects of bioextraction, the cell engineering is accompanied by the modification of culture condition and feedstocks in order to bypass conventional approaches and their drawbacks, although these problems are yet to be solved, it can, however, be reduced by increasing the use of biotechnological approaches in bioextraction methods. The integration of biological with conventional approaches can decrease environment limitations and costs through genetically modified producers and culture optimization, and therefore establishing suitable and commercially viable extraction methods. However, PHB bioextraction through green technology may be advantageous over conventional methods with maximum impact on human health and environment. This review discusses about using bioextraction methods as green technologies for PHB extraction from bacterial producer cells with less environmental limitation.

Effect of physical, chemical and biological extraction methods on the physical behaviour of banana pseudo-stem fibres: Based on fibres extracted from five common Sri Lankan cultivars

This article presents the strength, diameter, elongation and tenacity variations of banana pseudo-stem fibres extracted from five common Sri Lankan cultivars. The banana plants that were selected represent the dry and wet climatic zones of Sri Lanka. Mixtures of all layers of stem from the selected cultivars were subjected to three different extraction methods. Decortication technique was used for mechanical extraction, sodium hydroxide was used for chemical extraction and pectinase enzyme was used for biological extraction. The mechanical extraction method resulted in coarser fibres, chemical extraction resulted in a 30% reduction in the fibre diameter, while the biologically extracted fibre presented a 40% increase in fibre strength compared with the mechanically extracted fibres. Scanning electron microscopy analysis revealed the presence of damaged fibrils in mechanical extraction and removal of binder material in the chemical and biological extraction methods. Furthermore, Fourier transform infrared spectroscopy analysis proved the removal of lignin in chemical and biological extraction. Different cultivars presented different behaviours in extensibility, which is common in natural fibres.

RELATION OF AVAILABLE SOIL NITROGEN TO RICE YIELD

Thirty-one surface soil samples from nine years of rate and ratio rice fertilization experiments at different locations in Louisiana were analyzed for their available-nitrogen content, using six chemical and two biological extraction methods. The relationship between the available soil nitrogen and rough rice yields was then investigated. Total soil nitrogen varied widely, ranging from 540 to 5460 parts per million. The average percentage recovery of total soil nitrogen (representing the available soil nitrogen), as determined by the various methods used, also ranged widely, from as high as 16.74 percent, by the hot alkaline permanganate method, to the lowest value of 1.08 percent, by boiling soils in 0.01 M CaCl2 solution. Good correlation coefficients were obtained, especially among the anaerobic incubation and each of the other extraction methods used. The acid hydrolysis method correlated the least with the other extraction methods. Highly significant correlation coefficients were obtained between the rough rice yields from the untreated plots (plots that received no nitrogen) and the available soil nitrogen determined by all the extraction methods. The best correlation was obtained with the anaerobic incubation method (r = 0.622). The rough rice yield in plots receiving 56 or more kilograms of nitrogen per hectare did not exhibit a significant relationship with the available soil nitrogen. Relationships between the rough rice yields at zero and 28 kg/ha N and the available soil nitrogen, as determined by the anaerobic incubation method, were better described by curvilinear models than by linear ones. The relationship was also established between yield increase from application of 112 kg/ha N (the level of nitrogen generally considered near optimum for rice in Louisiana) and available soil nitrogen determined by the anaerobic incubation method. With some reasonable degree of accuracy, yield increase could be predicted from the graph signifying this relationship.